Yellow dye and process of making same.



Patented November 10, 1903.

PATENT OFFICE.

JOSEPH TURNER, OF HUDDERSFIELD, ENGLAND.

YELLOW DYE AND PROCESS OF MAKING SAME.

STEGIFIGATION forming part of Letters Patent No. 743,778, dated November10, 1903.

Application filed April 10, 1903, Serial No. 152,068. (Specimena) To allwhom it may concern.-

Be it known that I, JOSEPH TURNER, a subject of the King of GreatBritain, residing at Huddersfield, in the county of York, England, haveinvented certain new and useful Improvements in the Manufacture of aYellow D yestud; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

This invention relates to the manufacture or production of a yellowdyestuff for dyeing fiber or fabrics.

The object of my invention is to produce a new and novel yellow dyestuffcapable of dyeing wool, silk, and jute in fine greenish-yellow shadeswhich are fast to light.

In the course of investigation I have found that meta dinitrodiphenylamin para sulfonic acid when nitrated under suitable conditionsyields a new yellow dyestuff capable of dyeing wool, silk, and jute infine greenish-yellow shades fast to light.

For the nitration of meta dinitro diphenylamin para sulfonic acidaccording to my invention I take one hundred parts, by weight, of theabove-mentioned dinitro diphenylamin sulfo-acid and dissolve same in onehundred and fifty parts of water, adding fifty parts of nitric acid. Themixture is then raised to a suitable temperature-say SO centigradeandmaintained at from 80 to 90 centigrade for about one hour. The end ofthe reaction is indicated by the dyestuff becoming partiallyprecipitated. The coloring-matter is separated by diluting with an equalbulk of water and adding common salt. After filtering the precipitate iswashed with salt water, 0 pressed, and dried.

I do not limit myself to the precise details or proportions of partsgiven in the foregoing example, as by employing, for instance, arelatively larger quantity of nitric acid and a lower temperature asimilar result will be obtained.

The dyestuff produced according to my invention shows thefollowing'characteristicsz a bright-yellow powder easily soluble in hotwater, from which it crystallizes in golden- 50 yellow span gles oncooling. It possesses great penetrative power and dyes perfectly level"I 3. The method of forming a yellow dyestuff,

which consists in treating an aqueous solution of meta dinitrodiphenylamin para sulfonic acid with nitric acid, then heating themixture, and treatingit with additional water and salt.

In testimony whereof I affix my signature in presence of two witnesses.

JOSEPH TURNER.

Witnesses:

HERBERT HANSON, 'THOMAS H. BARRON.

